Alert archive / South Carolina / Mesoscale Discussions in 2006
Mesoscale Discussion 921
The Storm Prediction Center issued this mesoscale discussion at May 21, 2006, 3:39 PM EDT for 10 counties in North Carolina; 33 counties in South Carolina. It was in force for 66 min.
The area
The outline as issued.
The facts
- Issued
- May 21, 2006, 3:39 PM EDT (19:39 UTC)
- Expired
- May 21, 2006, 4:45 PM EDT
- In force
- 66 min
- Issued by
- the Storm Prediction Center
All 43 counties
Anson County, NC, Bladen County, NC, Brunswick County, NC, Columbus County, NC, New Hanover County, NC, Pender County, NC, Richmond County, NC, Robeson County, NC, Scotland County, NC, Union County, NC, Aiken County, SC, Bamberg County, SC, Barnwell County, SC, Berkeley County, SC, Calhoun County, SC, Cherokee County, SC, Chester County, SC, Chesterfield County, SC, Clarendon County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Edgefield County, SC, Fairfield County, SC, Florence County, SC, Georgetown County, SC, Greenwood County, SC, Horry County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, Newberry County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC, Union County, SC, Williamsburg County, SC, York County, SC
The radar
The Columbia radar (KCAE), 96 km from the middle of the area, began a volume at 19:41 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Charleston AFB, SC (KCHS), launched 12:00Z, 7.7 hours before the alert went out and 112 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 12 J/kg
- Mixed-layer CIN
- -344 J/kg
- Mixed-layer LCL
- 1659 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 31 m²/s²
- 0-3 km storm-relative helicity
- 64 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 ACUS11 KWNS 211939 SWOMCD SPC MCD 211939 NCZ000-SCZ000-212045- MESOSCALE DISCUSSION 0921 NWS STORM PREDICTION CENTER NORMAN OK 0239 PM CDT SUN MAY 21 2006 AREAS AFFECTED...SC...SERN NC CONCERNING...SEVERE THUNDERSTORM WATCH 372... VALID 211939Z - 212045Z SEVERE THREAT CONTINUES ACROSS VALID PORTION OF WW AHEAD OF CURRENT STORM CLUSTER...WITH POTENTIAL EVOLUTION TO A MORE WIDESPREAD WIND DAMAGE THREAT/BOW ECHO DURING THE NEXT HOUR. AREAS WEST OF THIS ACTIVITY MAY BE DROPPED FROM CURRENT WATCH GIVEN CONVECTIVE STABILIZATION IN WAKE OF THESE STORMS. AREAS EAST OF THE WATCH TO THE SC/SERN NC COAST WILL NEED ADDITIONAL WATCH IN THE NEXT HOUR. PERSISTENT CLUSTER OF SEVERE THUNDERSTORMS CONTINUES TO MOVE/EVOLVE QUICKLY ESEWD ACROSS UPSTATE SC THIS AFTERNOON. ACTIVITY HAS A HISTORY OF LARGE HAIL...WITH LATEST RADAR/SATELLITE IMAGERY INDICATING OTHER RAPID DEVELOPMENT CONTINUING TO ADVANCE THIS BROKEN CLUSTER OF STORMS ESEWD ACROSS REMAINDER OF WW DURING THE NEXT 1-1.5 HOURS. STRONG HEATING AND LARGE T-TD SPREADS IN ADVANCE OF THIS ACTIVITY SUGGESTS WIND DAMAGE THREAT WILL BECOME MORE WIDESPREAD INTO THE CENTRAL SC...INCLUDING THE CAE AREA... AROUND 2030Z. THIS IS RECENTLY EVIDENCED BY INCREASE IN WIND DAMAGE REPORTS OVER THE PAST HALF-HOUR. EXTRAPOLATION USING CURRENT MOTION OF 290/45KT PLACES LEADING ACTIVITY EAST OF WW BY 2130Z. WITH PREVAILING WLY SURFACE WINDS...SEA BREEZE WILL REMAIN NEARER THE COAST AND ALLOW TEMPERATURES TO WARM TO NEAR 90F ACROSS ERN SC AND SERN NC AHEAD OF THIS ACTIVITY. GIVEN DEGREE OF HEATING AND MODERATE INSTABILITY...SEVERE THREAT IS EXPECTED TO MOVE ESEWD ACROSS THE NERN SC/SERN NC COAST EARLY THIS EVENING. THUS...WW WILL BE NEEDED IN THE NEXT HOUR. ..EVANS.. 05/21/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MHX...RAH...ILM...CHS...CAE...GSP... 33028108 33548198 34338242 35098173 35047988 34867833 34497771 33827786 32947888 32857992
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 8:47 PM EDT | Mesoscale Discussion | SPC | Buncombe, Burke, Cabarrus, Catawba, Cherokee, Clay and 17 more | 28 min |
| May 20, 9:04 PM EDT | Severe Thunderstorm Watch | SPC | Cherokee, Clay, Graham, Macon | 9 hr |
| May 20, 9:35 PM EDT | Mesoscale Discussion | SPC | Beaufort, Bladen, Brunswick, Carteret, Chatham, Columbus and 22 more | 55 min |
| May 21, 12:32 AM EDT | Mesoscale Discussion | SPC | Bladen, Cherokee, Clay, Columbus, Graham, Macon and 2 more | 88 min |
| May 21, 12:50 PM EDT | Mesoscale Discussion | SPC | Henderson, Polk, Transylvania | 55 min |
| May 21, 4:06 PM EDT | Severe Thunderstorm Watch | SPC | Anson, Bladen, Brunswick, Columbus, New Hanover, Pender and 3 more | 3 hr |
| May 21, 5:46 PM EDT | Mesoscale Discussion | SPC | Bladen, Brunswick, Columbus, New Hanover, Pender, Richmond and 2 more | 89 min |
| May 21, 1:22 PM EDT | Severe Thunderstorm Watch | SPC | Abbeville, Aiken, Anderson, Bamberg, Barnwell, Calhoun and 24 more | 5 hr |
Nearby
Mesoscale Discussions in South Carolina, 2006Mesoscale Discussions in North Carolina, 2006Every mesoscale discussion in 2006
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.